Sparse Regularized Optimal Transport without Curse of Dimensionality

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: González-Sanz, Alberto, Eckstein, Stephan, Nutz, Marcel
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913826076622848
author González-Sanz, Alberto
Eckstein, Stephan
Nutz, Marcel
author_facet González-Sanz, Alberto
Eckstein, Stephan
Nutz, Marcel
contents Entropic optimal transport -- the optimal transport problem regularized by KL diver\-gence -- is highly successful in statistical applications. Thanks to the smoothness of the entropic coupling, its sample complexity avoids the curse of dimensionality suffered by unregularized optimal transport. The flip side of smoothness is overspreading: the entropic coupling always has full support, whereas the unregularized coupling that it approximates is usually sparse, even given by a map. Regularizing optimal transport by less-smooth $f$-divergences such as Tsallis divergence (i.e., $L^p$-regularization) is known to allow for sparse approximations, but is often thought to suffer from the curse of dimensionality as the couplings have limited differentiability and the dual is not strongly concave. We refute this conventional wisdom and show, for a broad family of divergences, that the key empirical quantities converge at the parametric rate, independently of the dimension. More precisely, we provide central limit theorems for the optimal cost, the optimal coupling, and the dual potentials induced by i.i.d.\ samples from the marginals. These results are obtained by a powerful yet elementary approach that is of broader interest for Z-estimation in function classes that are not Donsker.
format Preprint
id arxiv_https___arxiv_org_abs_2505_04721
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Sparse Regularized Optimal Transport without Curse of Dimensionality
González-Sanz, Alberto
Eckstein, Stephan
Nutz, Marcel
Statistics Theory
Probability
62G05, 62R10, 62G30
Entropic optimal transport -- the optimal transport problem regularized by KL diver\-gence -- is highly successful in statistical applications. Thanks to the smoothness of the entropic coupling, its sample complexity avoids the curse of dimensionality suffered by unregularized optimal transport. The flip side of smoothness is overspreading: the entropic coupling always has full support, whereas the unregularized coupling that it approximates is usually sparse, even given by a map. Regularizing optimal transport by less-smooth $f$-divergences such as Tsallis divergence (i.e., $L^p$-regularization) is known to allow for sparse approximations, but is often thought to suffer from the curse of dimensionality as the couplings have limited differentiability and the dual is not strongly concave. We refute this conventional wisdom and show, for a broad family of divergences, that the key empirical quantities converge at the parametric rate, independently of the dimension. More precisely, we provide central limit theorems for the optimal cost, the optimal coupling, and the dual potentials induced by i.i.d.\ samples from the marginals. These results are obtained by a powerful yet elementary approach that is of broader interest for Z-estimation in function classes that are not Donsker.
title Sparse Regularized Optimal Transport without Curse of Dimensionality
topic Statistics Theory
Probability
62G05, 62R10, 62G30
url https://arxiv.org/abs/2505.04721